The present invention relates to fastener means for disposable absorbent articles, such as diapers, pants-type diapers, incontinence guards or the like. Disposable absorbent articles of this kind are normally comprised of a liquid-permeable outer sheet, a liquid-impermeable backing sheet and an absorbent core enclosed therebetween. The outer sheet and the backing sheet are normally joined together outside the edges of the absorbent core and together form a casing or envelope. The outer sheet may have the form of elastic pants having a waist opening and two leg openings and including an absorbent core and a non-elastic backing sheet. The article is normally elongated and has a front waist region, a rear waist region and a narrower crotch region situated therebetween. The article also includes different elastic devices, mainly at the side edges of the crotch region and at the end edges of the waist regions, the purpose of these devices being to improve the fit of the article around the leg openings and around the waist respectively.
The article is secured around the waist of the wearer with the aid of fastener means provided at the side edges of the waist regions. These fastener means may, for instance, have the form of adhesive tabs mounted on the side edges of the rear waist region and fastened to the front waist region of the article when the article is donned. The fastener means may alternatively have the form of mechanical devices, such as touch-and-close fasteners, e.g. Velcro.RTM. fasteners where one pile surface is comprised of hooks and is fastened to an adapted pile surface comprised of loops. The fastener means may also comprise press studs, other forms of studs, or buttons.
The aforesaid conventional fastener means are encumbered with many drawbacks.
Conventional fastener means are designed to close the article around the waist of the wearer. Seen generally, typical fastener means are comprised of a receiving element and an adhering element. The receiving element is mounted on each side edge of one waist region, normally the front waist region, and the adhering element is mounted on each side edge of the opposing waist region. The elements are fastened together and mutually connect the waist regions. When putting-on the article, the adhering element is pressed against the receiving element so that the elements stick together. The pressure is applied at right angles to the plane of the waist region, i.e. against the wearer's stomach.
One advantage afforded by the inventive fastener means is that the article is closed by deformation of one element parallel with the plane of the waist regions, without subjecting the wearer's body to any appreciable pressure.
Conventional fastener means are subjected to large shear forces in use, as a result of wearer body movement. The adhering element is normally fastened to the receiving element while the wearer stands in an upright or lies in a recumbent position. In these positions, both waist regions of the article are situated at generally the same height around the wearer's waist. The receiving element is most often mounted on the front waist-region of the article and the article is therewith closed and fastened in the vicinity of the wearer's stomach. When the wearer is seated, the front waist-region tends to move down and the rear waist-region tends to move up, which is a natural consequence of bending the body. This results in the occurrence of large shear forces between the adhering element and the receiving element. An attempt has been made to solve this problem, by providing the fastener elements with larger contact surfaces.
A clear advantage afforded by the inventive fastener means is that it is deformable even in a vertical direction and is able to follow the movements of the wearer, by contracting and stretching with no impairment to its fastening properties.
Another drawback with conventional fastener means is that the wearer is able to release the fastener easily at times which might prove hazardous, by simply tearing the fastener elements apart. This drawback is also eliminated by the inventive fastener means. In order to release an inventive fastener means, it is necessary to subject one fastener element to two forces in two different directions simultaneously, the first direction being parallel with the fastener element and the other direction being away from the wearer's body.
Another drawback with conventional fastener means, and then with adhesive tabs in particular, is that they lose some of their fastening ability when fastened and released repeatedly, or when coming into contact with skin cream or talcum powder, for instance. Mechanical fastener means are also difficult to locate on the article so as to obtain an optimal fit with regard to wearers of varying anatomies. In order to circumvent this problem, it is often necessary to provide the article with an otherwise unnecessarily wide receiving element, therewith adding considerable cost to the manufacture of the article. Excessively wide touch-and-close fastener surfaces also impair wearer comfort, because they are stiff, difficult to bend, inelastic, and also fasten readily to the wearer's and the nurse's clothing.
It is therefore apparent that the fastener means of absorbent articles, such as pants-type diapers, diapers, incontinence guards and like articles are in need of significant improvement.
The present invention eliminates all of the aforesaid drawbacks in an effective and efficient manner.